#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include<string.h>
int main()
{
    int n = 0;
    scanf("%d", &n);
    getchar();
    char pd[100] = { 0 };
    scanf("%s", pd);
    int f1 = 1, f2 = 1, f3 = 1, f4 = 1;
    int fb = 0, fs = 0, fn = 0;
    int i = 0;
    for (i = 0; i < strlen(pd); i++)
    {
        if ((pd[i] >= 'a' && pd[i] <= 'z') || (pd[i] >= 'A' && pd[i] <= 'Z') || (pd[i] >= '0' && pd[i] <= '9'))
        {
            ;
        }
        else
        {
            f1 = 0;
            break;
        }
    }
    if (pd[0] >= '0' && pd[0] <= '9')
    {
        f2 = 0;
    }
    if (strlen(pd) < 8)
    {
        f3 = 0;
    }
    for (i = 0; i < strlen(pd); i++)
    {
        if (pd[i] >= 'a' && pd[i] <= 'z' && fs == 0)
        {
            fs++;
        }
        if (pd[i] >= 'A' && pd[i] <= 'Z' && fb == 0)
        {
            fb++;
        }
        if (pd[i] >= '0' && pd[i] <= '9' && fn == 0)
        {
            fn++;
        }
    }
    if (fs + fb + fn < 2)
    {
        f4 = 0;
    }
    if (f1 + f2 + f3 + f4 == 4)
    {
        printf("YES");
    }
    else
    {
        printf("NO");
    }
    return 0;
}